Anonymous LDAP bind dosent work

We are trying out XWiki to replace our current wiki.
We want that XWiki only read our LDAP (like our other services).
LDAP with SSL works if we set

xwiki.authentication.ldap.bind_DN=cn={0},ou=Users,dc=domain,dc=com
xwiki.authentication.ldap.bind_pass={1}

but if we let this two empty, we get following error:

org.xwiki.contrib.ldap.XWikiLDAPException: Error number 0 in 5: LDAP bind failed with LDAPException.
        at org.xwiki.contrib.ldap.XWikiLDAPConnection.open(XWikiLDAPConnection.java:239)
        at org.xwiki.contrib.ldap.XWikiLDAPConnection.open(XWikiLDAPConnection.java:164)
        at org.xwiki.contrib.ldap.XWikiLDAPAuthServiceImpl.ldapAuthenticateInContext(XWikiLDAPAuthServiceImpl.java:557)
        at org.xwiki.contrib.ldap.XWikiLDAPAuthServiceImpl.ldapAuthenticate(XWikiLDAPAuthServiceImpl.java:373)
        at org.xwiki.contrib.ldap.XWikiLDAPAuthServiceImpl.authenticate(XWikiLDAPAuthServiceImpl.java:307)
        at com.xpn.xwiki.user.impl.xwiki.MyFormAuthenticator.authenticate(MyFormAuthenticator.java:297)
        at com.xpn.xwiki.user.impl.xwiki.MyFormAuthenticator.processLogin(MyFormAuthenticator.java:208)
        at com.xpn.xwiki.user.impl.xwiki.MyFormAuthenticator.processLogin(MyFormAuthenticator.java:190)
        at com.xpn.xwiki.user.impl.xwiki.XWikiAuthServiceImpl.checkAuth(XWikiAuthServiceImpl.java:239)
        at org.xwiki.contrib.ldap.XWikiLDAPAuthServiceImpl.checkAuth(XWikiLDAPAuthServiceImpl.java:167)
        at com.xpn.xwiki.XWiki.checkAuth(XWiki.java:4350)
        at org.xwiki.security.authorization.internal.XWikiCachingRightService.authenticateUser(XWikiCachingRightService.java:241)
        at org.xwiki.security.authorization.internal.XWikiCachingRightService.checkAccess(XWikiCachingRightService.java:271)
        at com.xpn.xwiki.XWiki.checkAccess(XWiki.java:4373)
        at com.xpn.xwiki.XWiki.prepareDocuments(XWiki.java:5799)
        at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:498)
        at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:289)
        at com.xpn.xwiki.web.LegacyActionServlet.service(LegacyActionServlet.java:114)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:764)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:122)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.wysiwyg.filter.ConversionFilter.doFilter(ConversionFilter.java:61)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.container.servlet.filters.internal.SetHTTPHeaderFilter.doFilter(SetHTTPHeaderFilter.java:63)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:208)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.resource.servlet.RoutingFilter.doFilter(RoutingFilter.java:132)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1787)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
        at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.base/java.lang.Thread.run(Unknown Source)
Caused by: com.novell.ldap.LDAPException: Invalid DN Syntax
        at com.novell.ldap.LDAPResponse.getResultException(LDAPResponse.java:407)
        at com.novell.ldap.LDAPResponse.chkResultCode(LDAPResponse.java:370)
        at com.novell.ldap.LDAPConnection.chkResultCode(LDAPConnection.java:3959)
        at com.novell.ldap.LDAPConnection.bind(LDAPConnection.java:1408)
        at com.novell.ldap.LDAPConnection.bind(LDAPConnection.java:1361)
        at org.xwiki.contrib.ldap.XWikiLDAPConnection.bind(XWikiLDAPConnection.java:429)
        at org.xwiki.contrib.ldap.XWikiLDAPConnection.open(XWikiLDAPConnection.java:235)
        ... 58 common frames omitted

Can someone explain why the anonymous LDAP read dosen’t work?